title: TWIST1 plays a pleiotropic role in determining the anaplastic thyroid cancer phenotype.
abstract: BACKGROUND
  Anaplastic thyroid carcinoma (ATC) is one of the most aggressive human tumors; it is characterized by chemoresistance, local invasion, and distant metastases. ATC is invariably fatal.
  
  
  OBJECTIVE
  The aim was to study the role of TWIST1, a basic helix-loop-helix transcription factor, in ATC.
  
  
  METHODS
  Expression of TWIST1 was studied by immunohistochemistry and real-time PCR in normal thyroids and well-differentiated, poorly differentiated, and ATC. The function of TWIST1 was studied by RNA interference in ATC cells and by ectopic expression in well-differentiated thyroid carcinoma cells.
  
  
  RESULTS
  ATCs up-regulate TWIST1 with respect to normal thyroids as well as to poorly and well-differentiated thyroid carcinomas. Knockdown of TWIST1 by RNA interference in ATC cells reduced cell migration and invasion and increased sensitivity to apoptosis. The ectopic expression of TWIST1 in thyroid cells induced resistance to apoptosis and increased cell migration and invasion.
  
  
  CONCLUSIONS
  TWIST1 plays a key role in determining malignant features of the anaplastic phenotype in vitro.
authors.affiliation: Dipartimento di Biologia e Patologia Cellulare e Molecolare c/o Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche, Università di Napoli Federico II, 80131 Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Salerno
authors.forename: Ginesa
authors.initials: G
authors.lastname: Garcia-Rostan
authors.forename: Sara
authors.initials: S
authors.lastname: Piccinin
authors.forename: Tammaro Claudio
authors.initials: TC
authors.lastname: Bencivenga
authors.forename: Gennaro
authors.initials: G
authors.lastname: Di Maro
authors.forename: Claudio
authors.initials: C
authors.lastname: Doglioni
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
authors.forename: Roberta
authors.initials: R
authors.lastname: Maestro
authors.forename: Alfredo
authors.initials: A
authors.lastname: Fusco
authors.forename: Massimo
authors.initials: M
authors.lastname: Santoro
authors.forename: Giuliana
authors.initials: G
authors.lastname: Salvatore
mesh_terms: D017209:Apoptosis / Q000235:genetics / Q000502:physiology; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D034622:RNA Interference; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology*; D014162:Transfection; D014404:Tubulin / Q000096:biosynthesis / Q000235:genetics; D051879:Twist-Related Protein 1 / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D012334:RNA, Neoplasm; C103173:TWIST1 protein, human; D014404:Tubulin; D051879:Twist-Related Protein 1